The brutality and violence portrayed in Heart of Darkness escalate from acts of cruelty inflicted upon the indigenous people of the Belgian Congo to "unspeakable" and unspecified atrocities. Kurtz, who symbolizes European imperialists, has systematically exploited humans for his gain. The natives are depicted with iron collars around their necks, left starving, beaten, and forced to endure soul-crushing and pointless labor, ultimately facing ruthless execution. Additionally, it is suggested that Kurtz has orchestrated human sacrifices, and the reader is confronted with the disturbing sight of severed human heads mounted on stakes leading to Kurtz's dwelling. Conrad implies that violence and cruelty surface when laws are absent, and individuals are driven by their savage instincts. Driven by greed and self-deification, Kurtz loses control in a lawless environment. (©2004 eNotes.com) In such conditions, anything becomes possible, and Conrad reveals the profound cruelty and boundless violence that reside within the depths of the human soul.